R9 290 power supply?

Vitric9

Distinguished
I have seen that on sites that the R9 290 and R9 290x both would need a recommended PSU of 750w and that is for the reference PCB. I imagine that the non reference design might differ from this as brands like Asus Direct CUII would have better power delivery. It is always a good things to have a little extra wattage anyway. The R9 290 consumes a lot of power compared to it's Nvidia rival the GTX 780. I think the TDP for the 290 is about 275w but I have seen threads of it going past 300w.